ANCIENT WATER LEVELS OF CHAMPLA IN— HUDSON VALLEYS 157 



How of the Laurentide stream of ice through the Ohamplain 

 valley. In the village of Port Henry, near the Lake Ohamplain 

 and Mineville Railroad station, well developed nearly easiwest 

 glacial striae indicate a movement later than the main glacia- 

 lion and normal toi it. The striation referred to is n. G8° e. 

 Again J mile south of McKenzie brook along the street between 

 the 300 and 500 foot contour lines, glacial striae occur having a 

 more nearly east and west (n. 83° e.) direction. In the south 

 western corner of the Port Henry quadrangle, just south of the 

 red schoolhouse, glacial striae with a course n. 43° e. cover a 

 well worn ledge. Beginning on the north again in the bed of 

 Mill brook at a point north of the road crossing the stream 

 about J mile southwest of the race track, there are glacial 

 striae running n. 80° w. South of the road crossing, striae of 

 the northsouth set occur. These localities are shown on the 

 accompanying map [pi. 16]. 



Northwest of Tort Henry at a distance of 1 mile begins a 

 spur of foothills at the western base of which runs Bartlett 

 brook, the north branch of Mill brook. The western slope of 

 this spur carries a well defined lateral moraine terrace which 

 projects beyond the rock hill on the level ground west of the 

 rare track. From this point, the surface of the terrace rises 

 rapidly to the northward for about a mile beyond which no 

 attempt has been made as yet to trace the deposit. The terrace 

 can be plainly seen from the Mineville Railroad near the upper 

 switch back. The presence of this terrace in this position seems 

 to indicate clearly that the margin of an ice mass rested against 

 this western slope of the spur. One mile south of the southern 

 end of this deposit, south of the valley of Mill brook and the 

 north branch of McKenzie brook, the land rises to the 800 foot 

 contour line and is crested with a recognizable hummocky 

 moraine. 



Three hypotheses suggest themselves at once in the explana- 

 tion of the peculiar striation of this area. First, the abnormal 

 striae were produced by the westward protrusion of the margin 

 of the Champlain lobe at a time when it was mainly confined to the 

 walls of the lake valley and pressed against though it did not 

 overtop the foothills. Wherever a low place in the valley wall 



